First past the post system- General Elections The plurality voting system is a system used to elect members of a parliament which is based on single member constituencies. The most common system, used in the Uk as well as other countries such as the USA and Canada, is first past the post or winner-take-all, a voting system in which a single winner is chosen in a given constituency by having the most votes, regardless of whether or not he or she has a majority of votes. Supplementary Vote System – London mayor election With the supplementary vote, there are two columns on the ballot paper - one for the